from os import listdir,chdir,rename,getcwd

def addSuffix(p):
    chdir(p)
    fullname=listdir()
    counter=0
    for i in fullname:
        sname=i.split('\\')[-1]
        tname=sname+'.mp4'
        rename(sname,tname)
        counter+=1
    print('processed files:\n')
    print(counter)


def main():
    pathof=input(r'the path of the folder:Example:c:\temp'+'\n')
    addSuffix(pathof)
    
if __name__ == '__main__':
    main()
